Developmental disturbances of the Teeth

1. DEVELOPMENTA L DISTURBANCES OF THE TEETH Prepared by: Dr. Rea Corpuz

2. Developmental Disturbances  (1) Size  (2) Number and Eruption  (3) Shape/Form  (4) Defects of Enamel and Dentin

3. Size  Microdontia  Macrodontia

4. Size  Microdontia  (1) True Generalized Microdontia  (2) Relative Generalized Microdontia  (3) Focal or Localized Microdontia

5. (1) True Generalized Microdontia  all teeth are smaller than normal  occur in some cases of pituitary dawrfism  exceedingly rare  teeth are well formed

6. (2) Relative Generalized Microdontia  normal or slightly smaller than normal teeth  are present in jaws that are somewhat larger than normal

7. (3) Focal/Localized Microdontia  common condition  affects most often maxillary lateral incisior + 3rd molar  these 2 teeth are most often congenitally missing

8. (3) Focal/Localized Microdontia  common forms of localized microdontia is that which affects maxillary lateral incisior  peg lateral  instead of parallel or diverging mesial + distal surfaces

9. (3) Focal/Localized Microdontia  sides converge or taper together incisally  forms cone-shaped crown  root is frequently shorter than usual

10. Size  Microdontia  Macrodontia

11. Size  Macrodontia  (1) True Generalized Macrodontia  (2) Relative Generalized Macrodontia  (3) Focal or Localized Macrodontia

12. (1) True Generalized Macrodontia  all teeth are larger than normal  associated with pituitary gigantism  exceedingly rare

13. (2) Relative Generalized Macrodontia  normal or slightly larger than normal teeth in small jaws  results in crowding of teeth  insufficient arch space

14. (3) Focal/Localized Macrodontia  uncommon condition  unknown etiology  usually seen with mandibular 3rd molars

16. Number and Eruption  Supernumerary  Anodontia  Impaction

17. Number and Eruption  Supernumerary  results from continued proliferation of permanent or primary dental lamina to form third tooth germ  teeth may have: • normal morphology • rudimentary • miniature

18. Number and Eruption  Supernumerary  more often in permanent dentition than primary dentition  more in the maxilla than in mandible

19. Number and Eruption  Supernumerary  may be impacted erupted or impacted  because of additional tooth bulk, it causes: • malposition of adjacent teeth • prevent their eruption

20. Number and Eruption  Supernumerary  many are impacted • characteristically found in cleidocranial dysostosis

21. Number and Eruption  Supernumerary  Mesiodens  Fourth molar •Maxillary Paramolar • Distomolar or Distodens  Mandibular Premolar  Maxillary lateral incisors

22. Number and Eruption  Supernumerary  Mandibular central incisors  Maxillary Premolars

23. Mesiodens  most common supernumerary tooth  tooth situated between maxillary central incisors  singly  paired  erupted or impacted 

24. Mesiodens  small tooth  cone-shaped crown  short root

25. Fourth Molar  2nd most common  situated distal to 3rd molar  small rudimentary tooth, but may be of normal size  mandibular 4th molar also is seen occasionally, but less common than maxillary molar

26. Paramolar  small + rudimentary  situated bucally or lingually to one of the maxillary molars  interproximally between 1st + 2nd or 2nd + 3rd maxillary molars

27. Distomolar/Distodens  molar located distal to molar

29. Number and Eruption  Anodontia  lack of tooth development  absence of teeth

30. Number and Eruption  Anodontia  Complete Anodontia  Partial Anodontia • Hypodontia • Oligodontia  Pseudoanodontia  False Anodontia

31. Complete Anodontia  when all teeth are missing  rare  often associated with a syndrome known as hereditary ectodermal dysplasia

32. Hypodontia  lack of development of one or more teeth

33. Oligodontia  lack of development of six or more teeth

34. Pseudoanodontia  when teeth are absent clinically because of impaction or delayed eruption

35. False Anodontia  when teeth have been exfoliated or extracted

37. Number and Eruption  Impaction  most often affects the mandibular 3rd molars + maxillary canines  less commonly: • premolars • mandibular canines • second molars

38. Number and Eruption  Impaction  occurs due to obstruction from crowding  from some other physical barrier  occasionally, may be due to an abnormal eruption path, presumably because of unusual orientation of

39. Number and Eruption  Impaction  Ankylosis

40. Ankylosis  fusion of a tooth to surrounding bone  with focal loss of periodontal ligament, bone + cementum become inextricably mixed  cause fusion of tooth to alveolar bone

42. Shape and Form  Crown  Root

43. Shape and Form  Crown  Fusion  Gemination  Taurodontism  Talon’s Cusp  Leong’s Cusp

44. Shape and Form  Crown  Dens Invaginatus  Peg-shaped Lateral  Hutchinson Incisor  Mulberry Molar

45. Shape and Form  Root  Concresence  Enamel Pearl  Dilaceration  Flexion  Ankylosis

46. Fusion  joining of 2 developing tooth germs  resulting in a single large tooth structure  may involve entire length of teeth  or may involve roots only, in which case cementum + dentin are SHARED

47. Fusion

48. Gemination  fusion of 2 teeth from a single enamel organ  partial cleavage  appearance of 2 crowns that share same root canal  trauma has been suggested as possible cause, the cause is still unknown

49. Taurodontism  variation in tooth form:  elongated crowns  apically displaced furcations • resulting in pulp chambers that have apical occlusal height

50. Taurodontism  may bee seen as isolated incident in families  associated with syndromes such as  Down syndrome  Klinefelter’s syndrome

51. Taurodontism  little clinical significance  No treatment is required

52. Dens Evaginatus  Talon’s Cusp  Leung’s Premolar

53. Talon’s Cusp  well-delineated additional cusp  located on the surface of an anterior tooth  extends at least half the distance from CEJ to incisal edge

54. Leung’s Cusp  developmental condition  clinically as an accessory cusp or a globule  located on occlusal surface between buccal + lingual cusps of premolars  unilaterally or bilaterally

55. Dens Invaginatus (Dens in Dente)  deep surface invagination of crown or root that is lined by enamel  2 forms:  coronal  radicular

56. Dens Invaginatus (Dens in Dente)  depth varies from slight enlargement of cingulum to a deep infolding that extends to apex  historically, it has been classified into 3 major types:  Type I  Type II  Type III

57. Dens Invaginatus (Dens in Dente)  Type I • confined to the crown  Type II • extends below cemento enamel junction • ends in a blind sac • may or may not communicate with adjacent dental pulp

58. Dens Invaginatus (Dens in Dente)  Type III • extends through the root • perforates in the apical or lateral radicular area without any immediate communication with pulp

59. Peg-Shaped Lateral  undersized lateral incisor  smaller than normal  occurs when permanent lateral incisors do not fully develop

60. Peg-Shaped Lateral

61. Hutchinson’s Incisor  characteristic of congenital syphilis  lateral incisors are peg-shaped or screwdriver-shaped  widely spaced  notched at the end  with a crescent-shaped deformity

62. Hutchinson’s Incisor  notches on their biting surfaces  named after Sir Jonathan Hutchinson  English surgeon + pathologist who 1st described it

63. Mulberry Molar  dental condition usually associated with congenital syphilis  characterized by multiple rounded rudimentary enamel cusps on permanent 1st molars

64. Mulberry Molar  dwarfed molars with cusps covered with globular enamel growths  giving the appearance of a mulberry

65. Shape and Form  Root  Concresence  Enamel Pearl  Dilaceration  Flexion  Ankylosis

66. Concrescence  2 fully formed teeth  joined along the root surfaces by cementum  noted more frequently in posterior and maxillary regions

67. Concrescence  often involves a 2nd molar tooth in which its roots closely approximate the adjacent impacted 3rd molar  may occur before or after the teeth have erupted  usually involves only 2 teeth

68. Concrescence  diagnosis can frequently be established by roentgenographic examination  often requires no therapy unless union interferes with eruption; then surgical removal may be warranted since with fused teeth, extraction of one may result in extraction of the other

69. Enamel Pearls  droplets of ectopic enamel  or so called enamel pearls  may occasionally be found on roots of teeth  uncommon, minor abnormalities, which are formed on normal teeth

70. Enamel Pearls  occur most commonly in bifurcation or trifurcation of teeth  may occur on single-rooted premolar as well  maxillary molars are commonly affected than mandibular molars

71. Enamel Pearls  consist of only a nodule of enamel attached to dentin  may have a core of dentin containing pulp horn  may be detected on radiographic examination

72. Enamel Pearls  may cause stagnation at gingival margin but, if they contain pulp, this will be exposed when pearl is removed

73. Dilaceration  angulation or a sharp bend or curve in root or crown of a formed tooth  trauma to a developing tooth can cause root to form at an angle to normal axis of tooth  rare deformity

74. Dilaceration  movement of crown or of the crown and part of root from remaining developing root may result in sharp angulation after tooth completes development

75. Dilaceration  hereditary factors are believed to be involved in small number of cases  eruption generally continues without problems

76. Flexion  deviation or bend restricted just to the root portion  usually bend is less than 90 degrees  may be a result of trauma to the developing tooth

77. Ankylosis  also known as “submerged teeth”  fusion of a tooth to surrounding bone  deciduous teeth most commonly mandibular 2nd molars  undergone variable degree of root resorption

78. Ankylosis  have become ankylosed to bone  this process prevents their exfoliation + subsequent replacement by permanent teeth  after adjacent permanent teeth have erupted, ankylosed tooth appears to have submerged below level of occlusion

80. Amelogenesis Imperfecta  also known as:  Hereditary Enamel Dysplasia  Hereditary Brown Enamel  Hereditary Brow Opalescent Teeth

81. Amelogenesis Imperfecta  group of conditions caused by defects in the genes encoding enamel matrix proteins  genes that encode for enamel proteins:  amelogenin mutated in  enamelin in patients  others with this condition

82. Amelogenesis Imperfecta  affects both dentition  deciduous  permanent  classified based on pattern of inheritance:  hypoplasia  hypomaturation  hypocalcified

83. Amelogenesis Imperfecta  No treatment except for improvement of cosmetic appearance

84. Hypoplastic Amelogenesis Imperfecta  inadequate formation of matrix  enamel is randomly:  pitted  grooved or very thin  hard + translucent  defects become stained but teeth are not especially susceptible to caries unless enamel is scanty and easily damaged

85. Hypoplastic Amelogenesis Imperfecta  reduced enamel thickness  abnormal contour  absent interproximal contact points  Radiographically:  enamel reduced in bulk  shows thin layer over occlusal + interproximal surfaces

86. Hypoplastic Amelogenesis Imperfecta  dentin + pulp chambers appear normal  no treatment is necessary

87. Hypomaturation Amelogenesis Imperfecta  enamel is normal in form on eruption but:  opaque  white to brownish-yellow  softer than normal  tends to chip from underlying dentin

88. Hypomaturation Amelogenesis Imperfecta  Radiographically:  affected enamel exhibits radiodensity similar to dentin

89. Hypocalcified Amelogenesis Imperfecta  enamel matrix is formed in normal quantity  poorly calcified  when newly erupted:  enamel is normal in thickness  normal form  but weak  opaque or chalky in appearance

90. Hypocalcified Amelogenesis Imperfecta  with years of function:  coronal enamel is removed  except for cervical portion that is occasionally calcified better  Radiographically:  density of enamel + dentin are similar

91. Dentinogenesis Imperfecta  also known as “Hereditary Opalascent Dentin”  due to clinical discoloration of teeth  mutation in the dentin sialophosphoprotein  affects both primary + permanent dentition

92. Dentinogenesis Imperfecta  have blue to brown discoloration  with distinctive translucence  enamel frequently separates easily from underlying defective dentin

93. Dentinogenesis Imperfecta  Radiographically:  bulbous crowns  cervical constriction  thin roots  early obliteration of roots canals + pulp chambers

94. Dentinogenesis Imperfecta  Treatment:  prevent loss of enamel + subsequent loss of dentin through attrition  cast metal crowns on posterior  jacket crowns on anterior teeth

95. Dentinogenesis Imperfecta  Classification:  Type I  Type II  Type III

96. Type I Dentinogenesis Imperfecta  occurs in families with Osteogenesis Imperfecta  primary teeth are more severely affected than permanent teeth

97. Type I Dentinogenesis Imperfecta  Radiographically:  partial or total obliteration of pulp chambers + root canals  by continued formation of dentin  roots may be short + blunted  cementum, periodontal membrane + bone appear normal

98. Type II Dentinogenesis Imperfecta  never occurs in association with osteogenesis imperfecta unless by chance  most frequently referred to as hereditary opalascent dentin  only have dentin abnormalities and no bone disease

99. Type II Dentinogenesis Imperfecta  Radiographically:  partial or total obliteration of pulp chambers + root canals  by continued formation of dentin  roots may be short + blunted  cementum, periodontal membrane + bone appear normal

100. Type III Dentinogenesis Imperfecta  “Bradwine type”  racial isolate in Maryland  multiple pulp exposures in deciduous not seen in type I or II  periapical radiolucencies

101. Type III Dentinogenesis Imperfecta  enamel appears normal  large size of pulp chamber is due not to resorption but rather to insufficient + defective dentin formation

102. Dentin Dysplasia  also known as “Rootless Teeth”  rare disturbance of dentin formation  normal enamel  atypical dentin formation  abnormal pulpal morphology  hereditary disease

103. Dentin Dysplasia  Classification:  Type I (Radicular Type)  Type II (Coronal Type)

104. Type I (Radicular Type)  both dentitions are of normal color  periapical lesion  premature tooth loss may occur because of short roots or periapical inflammatory lesions

105. Type I (Radicular Type)  Radiographically:  roots are extremely short  pulps almost completely obliterated  periapical radiolucencies: • granulomas • cysts • chronic abscesses

106. Type II (Coronal Type)  color of primary dentition is opalescent  permanent dentition is normal  coronal pulps are usually large (thistle tube appearance)  filled with globules of abnormal dentin

107. Type II (Coronal Type)  Radiographically: (Deciduous)  roots are extremely short  pulps almost completely obliterated (Permanent)  abnormally large pulp chambers in coronal portion of tooth

108. Regional Odontodysplasia  also known as:  Odontogenic Dysplasia  Odontogenesis Imperfecta  Ghost Teeth

109. Regional Odontodysplasia  one or several teeth in a localized area are affected  maxillary teeth are involved more frequently than mandibular area  etiology is unknown

110. Regional Odontodysplasia  teeth affected may exhibit a delay or total failure in eruption  shape is altered, irregular in appearance

111. Regional Odontodysplasia  Radiographically:  marked reduction in radiodensity  teeth assume a “ghost” appearance  both enamel + dentin appear very thin  pulp chamber is exceedingly large

112. Regional Odontodysplasia  Treatment:  poor cosmetic appearance of teeth  extraction with restoration by prosthetic appliance

113. Shell Tooth  normal thickness enamel  extremely thin dentin  enlarged pulps  thin dentin may involve entire tooth or be isolated to the root  most frequently in deciduous

114. References:  Books  Cawson, R.A: Cawson’s Essentials of Oral Oral Pathology and Oral Medicine, 8th Edition • (pages 24-36)  Neville, et al: Oral and Maxillofacial Pathology 3rd Edition • (pages 77-113)  Regezi, Joseph et al: Oral Pathology, Clinical Pathological Correlations 5th Edition • (pages 361-373)  Shafer, et al: A textbook of Oral Pathology, 3rd Edition • (pages 37-69)

Developmental disturbances of the Teeth

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Developmental disturbances of the Teeth

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